This invention relates to an outboard motor and more particularly to an improved outboard motor powered by a gaseous fuel and having an underwater engine.
It has been proposed to provide a type of outboard motor that is powered by a gaseous fueled two cycle internal combustion engine, which engine is positioned below the body of water in which the watercraft is operating. This type of motor has a relatively small displacement and low power engine and because of its underwater operation, it is quite quiet. For example, this type of engine can have a displacement of about ten cubic centimeters and develop approximately one-half of a horsepower.
Although the underwater location has the advantages of providing silencing and, also, cooling without the provision of a separate cooling jacket for the engine and the need to circulate water through it or the use of finning as with air-cooled engines, the positioning of the engine under the body of water or at least partially in a submerged location can give rise to wide variations in engine operating temperature. In fact, over cooling of the engine can result.
It is, therefore, a principal object of this invention to provide an outboard motor of this type wherein the engine is adequately cooled but over cooling is avoided.
It is a further object of this invention to provide an improved arrangement for maintaining the temperature of an otherwise uncooled internal combustion engine for utilization in an outboard motor of this type.
When the internal combustion engine is positioned beneath or at least partially beneath the water level, there is a problem in assuring good water sealing of the engine. This is primarily due to the fact that the exhaust gases from the engine are normally discharged under water so as to provide silencing for the exhaust system and cooling. However, this means that the water may come into proximity with the engine and thus, with previously proposed constructions, complete water sealing of the engine and all components has been necessary. This, of course, raises the cost of the engine.
It is, therefore, a still further object of this engine to provide an improved outboard motor having an under water position internal combustion engine and wherein the engine itself and its exhaust system are such that the engine need not be fully water tight.
When the internal combustion engine is powered by a pressured gaseous fuel, it is very desirable to provide a pressure regulator to regulate the pressure of the fuel delivered to the engine. As is well known, this type of pressurized fuel is contained within a container in a partially liquid form. As the fuel is consumed from the container, the pressure of the fuel can decrease and thus, unless some form of regulation is incorporated, the fuel/air mixture may vary as the fuel is consumed from the container.
A conventional type of pressure regulator employs a diaphragm which is operated so as to maintain uniform fuel pressure regardless of the amount of fuel maintained in the container. However, it is well known that outboard motors are mounted for some form of tilt movement so as to adjust the degree of submersion of the propeller. When the tilt condition of the outboard motor is changed and with prior art type of constructions, the degree of tilt can alter the operation of the pressure regulator and result in variations in fuel/air mixture depending upon the tilt relationship.
It is, therefore, a further object of this invention to provide an improved regulating system for the pressurized gaseous fuel source of an outboard motor fueled by such a fuel.
It is a further object of this invention to provide an improved pressure regulator and mounting arrangement therefor for a gaseous fuel propelled outboard motor.
In addition to the problem of pressure regulation with respect to tilt movement of the outboard motor, it is also undesirable to have the pressurized fuel container tilt during operation. As has been previously noted, the fuel is contained within the pressure container under pressure and some, if not most, of the fuel may be liquified because of the high pressures employed. However, if the tilt of the fuel container is such that liquid is present at its discharge end, then erratic and unacceptable variations in fuel supply may result.
It is, therefore, a still further object of this invention to provide an improved gaseous fuel supplied outboard motor.
It is a further object of this invention to provide an improved mounting arrangement for the gaseous fuel of such an outboard motor wherein the fuel will not be subject to the tilt operation of the motor.
The type of outboard motor as thus far described is not normally employed with the type of watercraft on which conventional outboard motors are utilized. Conventional outboard motors are normally utilized with watercraft having transoms and the outboard motor carries a clamping bracket that it detachably connected to the transom. In fact, in many applications the mounting bracket of the outboard motor may be relatively permanently attached to the transom. However, with the type of outboard motor disclosed herein the motor is frequently used on a type of watercraft that does not have a transom such as a canoe or the like. Therefore, side mounting of the outboard motor is frequently utilized with this type of watercraft. However, there are many times when it is desirable to move the outboard motor so that it is not in the body of water in which the watercraft is operating. It is, in fact, desirable if the outboard motor may be mounted in such a way that the drive portion can be completely swung in a convenient fashion internally of the hull of the watercraft.
It is, therefore, a still further object of this invention to provide an improved mounting arrangement for an outboard motor that permits it to be conveniently and easily swung from a side of the hull on which it is suspended internally of the outer periphery of the hull without necessitating detachment from the hull.